Tweak memcache initialization

Author: Jamie Snape

core/GlobalController.php

@@ -117,7 +117,7 @@ public function preDispatch()
     if(!$this->isDebug())
       {
       $frontendOptions = array('automatic_serialization' => true, 'lifetime' => 86400);
-      if(extension_loaded('memcache'))
+      if(extension_loaded('memcache') || session_save_path() === 'Memcache')
         {
         $cache = Zend_Cache::factory('Core', 'Memcached', $frontendOptions, array());
         }
@@ -128,7 +128,7 @@ public function preDispatch()
       else
         {
         $cacheDir = UtilityComponent::getCacheDirectory() . '/db';
-        if(is_writable($cacheDir))
+        if(is_dir($cacheDir) && is_writable($cacheDir))
           {
           $backendOptions = array('cache_dir' => $cacheDir);
           $cache = Zend_Cache::factory('Core', 'File', $frontendOptions, $backendOptions);

library/Zend/Cache/Backend/Libmemcached.php

@@ -96,7 +96,7 @@ class Zend_Cache_Backend_Libmemcached extends Zend_Cache_Backend implements Zend
      */
     public function __construct(array $options = array())
     {
-        if (!extension_loaded('memcached')) {
+        if (!extension_loaded('memcached') || session_save_path() !== 'Memcache') {
             Zend_Cache::throwException('The memcached extension must be loaded for using this backend !');
         }
 

library/Zend/Cache/Backend/Memcached.php

@@ -119,7 +119,7 @@ class Zend_Cache_Backend_Memcached extends Zend_Cache_Backend implements Zend_Ca
      */
     public function __construct(array $options = array())
     {
-        if (!extension_loaded('memcache')) {
+        if (!extension_loaded('memcache') || session_save_path() !== 'Memcache') {
             Zend_Cache::throwException('The memcache extension must be loaded for using this backend !');
         }
         parent::__construct($options);